25 replies to this topic

[stef]

hey.

im pretty sure i'm gonna get an hif38 off minidaves with the throttle plate and spacer, and was wondering if theress any complications when switching.

im on a stage 1 998 that urgently needs rolling road, hence i'm getting one of these because i cant be arsed to sort out the air leak in my current carb.

so i'll need new gaskets for carb to spacer block and spacer to carb.

2 new manifold studs. just normal ones? because minispares do longer ones etc.

i guess i need a new throttle cable? one with a white plastic thingy to bodge into the throttle plate? anyone point me to a linky?

can i use my current AAA needle or do i need a different one because its a different carb?

and finally, on my carb i have throttle, choke, easy peasy. i've also got fuel and a vaccum pipe. fuel goes into the float chamber, so i'm assuming i'll need to extend this to go straight onto the carb?

does the HIF have a vaccum intake, or do i block this off/put one of those lil breathers on it to look cool.

any other connections or things i need to do?

sorry its long winded, but i want to make sure before i shell out.

cheers

[fikus01]

i think you got it all there!! yes you can use the same AAA needle.

unless you're planning to plug in the breather system to the carb you'll need to block up that hole on the carb !! cant remember anything else really!!

fuel input is the lower of the fuel connections and the breather/overflow is the upper one!!

throttle cable link below!! the click here thingy wouldnt work!!

http://www.minispare....aspx?pid=35088

also advisable would be a stub stack!! it aids airflow into the carb!!

[Big_Adam]

wouldn't say a stub stack imporves airflow. cuts a little induction noise but thats about it.

[fikus01]

noise = turbulance = less airflow going into the carb!!

made a noticable difference on mine once it was setup!

[stef]

ok cool, so the hif DOES have a bit on it for me to plug in the breather pipe? sorry bit confusing

also i'm assuming its got a bit on it so i can plug the vaccum advance on my dizzy into it?

it says that cable is for a metro carb... didnt realise the HIF was for a metro.

i suppose i'll have to buy a stub stack, everyone seems to go on about them. they arent expensive so we shall see if they do really make a difference.

cheers for the replies!

[biggav]

Vizard says they make a difference... and backs up his comments with scientific explanation!!!!

I have one on my carb.... but that said, i'll do anything for more horses!!!!!

[fikus01]

its all pretty similar to a hs carb when u look at what goes in and comes out of it!!

i think the hs carb was always used on minis in 1 1/2" form but on metros it was hif, purely because if space issues with the bulkhead!! just try fitting a hif in there with a std filter and stuff!!

when i fitted this cable to my mates car his std mini throttle cable mounting hole was a little loose anyway so we jsut knocked it out and shoved the metro cable thru the hole that was left!! failing that i think the white plastic bit will come off if u ask it nicely with some pliers!!

p.s. have u got the hif cable mountings bracket??

[RacingGreen]

As fikus said, when a hif is fitted there can be issues with the carb hitting the bulkhead.

When rover fitted them to the rsp coopers they had to move the engine 5/8"s further forward to stop the carb hitting the bulkhead. But go for it and see how much room you have.

[Big_Adam]

made a noticable difference on mine once it was setup!

Ah, mines not set up right.

[998dave]

Vizard says they make a difference... and backs up his comments with scientific explanation!!!!

I have one on my carb.... but that said, i'll do anything for more horses!!!!!

Ignoring Vizard they do make a difference anyway, it's all about flow through a choke... I'd draw and attach a photo, but can't be bothered, basically if you have 90 degree angle the air doesn't flow through the opening in a laminar manner (nice smooth lines), and you get turbulence on the edge of the hole, effectively reducing the diameter of the hole the air can flow through, with a stub stack you smooth this flow and reduce turbulence (and noise), and will get a better flow in to the hole.

It's the same theory that is used when porting heads, smootheing everything out and getting nice flowing lines in and out of your engine...

Dave

Oh yeah.
There is a bit on the HIF38 for your vacuum advance.
The little white bit of plastic will hold the throttle cable in the cable bracket.
You may have to modify (read bend) the heat shield IF you've got an LCB exhaust fitted.
You can use the same needle.
You should clean the carb out before using it, get some carb cleaner and a compressed air line if you can.
If you're fitting a K&N you can modify the cable bracket to remove the air filter fitting bit (use a hacksaw), this will tidy up that bit of the engine bay a little.

Anything else?

Dave

Edited by 998dave, 29 October 2006 - 11:08 AM.

[stef]

well, clears up everything i need to know. thanks very much.

so, if it hits the bulkhead is it gonna hit the bottom of the round bit that allows for the filter? if it does, i modify it. so i'm guessing the use of a hammer and/ or hacksaw? would it only be a small amount or large amount, i dont want to lose strength in it.

[998dave]

well, clears up everything i need to know. thanks very much.

so, if it hits the bulkhead is it gonna hit the bottom of the round bit that allows for the filter? if it does, i modify it. so i'm guessing the use of a hammer and/ or hacksaw? would it only be a small amount or large amount, i dont want to lose strength in it.

Can you explain that better?

By round bit do you mean the elbow behind the carb? That shouldn't hit, I'd expect the bottom of the carb to, although that shouldn't either, I've just fit an HIF44 to mine and have a good 5mm clearance, on a standard MG manifold, with spacer fitted... No problem.

D

[fikus01]

mg manifolds give more room to play than most because they are quite a short manifold! i think vizzards words were "its almost perfect but about 1inch too short"

torquemaster is the worse for fitment because it tilts the carb up at an angle!! maniflow is pretty much like a copy of the mg in its lengeth and shape!! id use the maniflow for a 998 and the mg for a 1275 purely because the port sizez on an mg are probably a little large for a 998

[stef]

mg manifolds give more room to play than most because they are quite a short manifold! i think vizzards words were "its almost perfect but about 1inch too short"

torquemaster is the worse for fitment because it tilts the carb up at an angle!! maniflow is pretty much like a copy of the mg in its lengeth and shape!! id use the maniflow for a 998 and the mg for a 1275 purely because the port sizez on an mg are probably a little large for a 998

well that sucks, i've got a minisport stage 1 so im pretty sure the manifold is like a torquemaster. i'm not really willing to pay out just for a new manifold when mine is fine.

i meant the bit on the bulkhead that has the circle cut into it, behind the carb, e.g my cone filter would hit the bulkhead if it was not there.

so, i'm assuming the bottom of the float bowl will hit onto the big square piece of bulkhead, which means that im screwed? or is there any way i can modify things to fit?

does the carb need to have the spacer?

cheers,
Stef

[Jimmyarm]

does the carb need to have the spacer?

No, it is there purely to prevent heat transfer from the manifold, which isnt such an issue when you are using an aftermarket alloy manifold.

You can get thinner ones, you will need shorter manifold - carb studs though as the originals will be too long.

Edited by Jimmyarm, 30 October 2006 - 04:14 PM.